FRIDAY, March 6, 2015 (HealthDay News) -- High levels of small-particle air pollution can increase your risk for narrowing of the neck (carotid) arteries, which may raise your risk for stroke, a new study says.

Researchers analyzed the results of cardiovascular screening tests from more than 300,000 people in New York, New Jersey and Connecticut.

Those who lived in areas with the highest levels of air pollution were 24 percent more likely to have narrowing of the carotid arteries than those in areas with the lowest levels of air pollution. The carotid arteries deliver blood to the brain.

The investigators focused on a type of air pollution called fine particulate matter -- particles of pollution smaller than 2.5 micrometers in diameter. Fine particulate matter is the most common type of air pollution and comes from sources such as car exhaust and the burning of wood or coal.

The study is scheduled for presentation March 16 at the annual meeting of the American College of Cardiology (ACC) in San Diego. It also appears in the Journal of the American College of Cardiology.

"Our study adds to the growing body of evidence that air pollution is a significant risk factor for cardiovascular disease," said lead author Dr. Jonathan Newman, a cardiologist at NYU Langone Medical Center in New York City.

"It shows that a person's cardiovascular risk is not only associated with their genes, health behaviors and lifestyle choices, it also depends to some extent on the world we live in and the air we breathe," he said in an ACC news release.

The results draw attention to the importance of reducing air pollution, Newman said.

"If you're in good health, the level of air pollution we see in most parts of the United States probably doesn't pose a significant health risk to you. But for people who are very young, very old or have other medical problems, air pollution could be a significant source of cardiovascular disease risk," he added.

Outdoor and indoor air pollution is associated with about 8 million premature deaths worldwide each year, according to the World Health Organization.